Miscellany

It’s Been a While

Matt Herod September 2, 2016

It’s been a long time since my last post. This is mainly due to the ridiculously busy summer I have had. The biggest thing was getting married, but the honeymoon, work trips and deadlines as well as working on a few papers kept me pretty occupied. I’m sad to say that blog updates dropped lower on my priority list then I would’ve liked.

In any case, I am going to try to get back at it now that life has settled down a bit. Stay tuned for some detailed posts on research, geopolls and other stuff. I am of course always open to guest posts so if anyone would like to volunteer I’d be more than happy to host.

In the meanwhile here is a great photo from my honeymoon on the Amalfi coast of Mt. Vesuvius taken from Sorrento. Maybe I’ll write about Pompeii….just a thought.

Looking across the Bay of Naples towards Mt. Vesuvius from Sorrento. Photo: Matt Herod

Blast from the Past: It’s all about scales

Matt Herod March 22, 2016

It has often been said that geology is the study of scales. Time scales, large scales, small scales and many others. Indeed, one of the most crucial parts of any photo or map is the scale. Furthermore, geologic concepts can be applied from the planet scale to the atomic scale and every size in between. What confuses most people though is not only do we work in terms of huge size/magnitude variations but we also work with huge temporal variations. Processes that can take billions of years to nanoseconds all have their place in geology. Perhaps this is part of what makes it such a fascinating science?

Anyway, I thought it might be fun to share a few variations in scale that I have noticed recently.

A large hoodoo in Dinosaur Provincial Park, Alberta. I would say it is around 5m high and the rock on top is at least 5m across if not larger. (Photo: Matt Herod)

Some smaller hoodoos also located in Dinosaur Provincial Park, Alberta. I woudl say these ones are about 50cm high. By the way, the round object between the two hoodoos at the back is a dinosaur vertabrae. Likely a Hadrosaur. (Photo: Matt Herod)

Some really small hoodoos. I found these on a recent recon trip to a sand pit north of Ottawa near Cantley, Quebec. (Photo: Matt Herod)

Pretty cool eh?! People generally think of hoodoos as big spectacular structures that look like they are performing an incredible act of balance. Hoodoos form through erosive processes on the soft sediment underlying a large rock. They can be formed by wind, rain, or freeze-thaw cycles that erode the soft sediment below the boulder. However, eventually the sediment directly beneath the rock/pebble is protected from above preserving the hoodoo.

Here is another example of how scale has nothing to do with process. What I mean by this is that the same process that forms large features is also capable of forming small ones, like the hoodoos above.

A medium size rat-tail at Cantley Quarry, Quebec. It is probably around 8m long and the rock in the front is about 1m. That is my co-TA, Brett, for scale. (Photo: Matt Herod)

This monster rat-tail is over 50m long! You can see the xenolith in the front where the rusty discolouration is. There is also a smaller rat-tail in the foreground. (Photo: Matt Herod)

A “micro” rat-tail. This tiny one is only a few cm’s long but it still has the same basic structure: comet shaped with an obstacle in the front. Although, in this case the obstacle is a mineral grain and not a gneiss boulder.

Okay, so hoodoos are not the only erosional feature than can be formed at a variety of scales. However, I think these rat-tails are even more impressive than the hoodoos. Rat tails are glacial erosion features that form underneath a glacier by vast, fast flowing rivers of glacial meltwater actually eroding the rocks and forming these streamlined features. The dominant bedrock in the area is a soft marble that contains xenoliths of hard Grenville gneiss. The gneiss acts as a barrier to the meltwater forcing it to flow around it. This protects the marble directly behind the xenolith and forms the rat-tail.

Scales don’t just vary in erosion features though. There are lots of other great examples of scale variation throughout geology.

Massive selenite crystals in the famous “cave of crystals” in Naica, Chihuahua, Mexico with a person for scale. (Image: Wikipedia)

Gypsum (Var.: Gypsum) Locality: Red River Floodway, Winnipeg, Manitoba, Canada (Source)

The gypsum crystals of the crystal cave were formed by heated groundwater that was evidently extremely saturated with respect to gypsum. I haven’t done the calculations about how insanely over saturated this water must have been to precipitate crystals this large, but maybe if I’m bored one day I’ll try it out. The chemical formula of gypsum is CaSO4 – 2 H2O. The water filled the cave and the crystals were able to precipitate around 500,000 years ago. The dating method used was U-Th disequilibrium dating.

I have a funny anecdote about the picture of the cave above. I remember when news of the cave hit the media. I was taking advanced mineralogy at the time and someone brought that picture in to show our prof and get his reaction. His first reaction, before doing any research, was that the picture was photoshopped and the cave did not exist. It just goes to show that a) this cave is incredible and b) it is possible to fool mineralogists sometimes.

Small fold in meta-sedimentary rock of the Pinnacle Formation in Sutton, Quebec. (Photo: Matt Herod)

Photo of yours truly demonstrating the curvature of this fold which is also in the Pinnacle Fm. in Sutton, Quebec (Photo: not Matt Herod, but with my camera)

Google Maps image of the Rideau Lakes area north of Kingston, Ontario. Notice the kilometre scale folding in the area and how the lakes conform to the structural geology of the area.

As you can see the study of geology is really all about scale. Every major geologic discovery is required to have context in terms of either the geologic time scale or size. I have given some examples of how size can vary regardless of process. If you have any examples of scales in geology I would love to hear about it. Please post in the comments below. If your example is in picture form I would be happy to add them to this post.

Thanks for reading! FYI, this post was originally published back in 2012.

Matt

GeoPoll: Who do you think most deserves the title “Father of Geology?”

Matt Herod January 26, 2016

It’s been a while since the last geopoll/post. Too long. Life has been busy for me though. I am just concluding an extremely short post-doc at Health Canada’s Canadian Radiological Monitoring Network and am starting a new job at the Canadian Nuclear Safety Commission next week. Suffice to say blogging has sadly slipped a bit lower on my list than I’d like. Plus it’s hockey and nordic season here in Ottawa.

At any rate, I though it high time to dust off one of my saved up poll ideas. Throughout my geological education the title “Father of Geology” has been bandied about in reference to several different founders of the science. When you google “Father of Geology” James Hutton is featured prominently. But is he really the true “Father of Geology”? I have heard the term applied to many others including: Charles Lyell, Charles Darwin, William Smith and more. Each of these men has made huge contributions to geosciences, but which do you think deserves to be recognized as the sole founder? By the way, when you google “Mother of Geology” you get James Hutton as the top result, sadly.

In no particular order, here are your choices.

James Hutton

Google’s choice for the title but not necessarily yours. James Hutton certainly does deserve a top spot in the “most important contributions to geoscience” power rankings, but just how high is up for discussion. The mind behind the principle of uniformitarianism, which despite its annoying name, is a crucial concept underpinning almost every aspect of geology. Hutton’s theory, simplistically put, states that processes in the present operated in the past. This gave early geologists great insight into the processes that formed the rocks, minerals and fossils they were discovering. It also opened the door to our understanding of geologic time, which is a central tenet of geology and underlies every aspect of the science.

Siccars Point, UK. The place where James Hutton found proof of uniformitariansm in the visible angular unconformity representing the missing time between the two formations. Source

Charles Lyell

Author of the famed text “Principles of Geology” in 1830 is a strong contender for the title without question. Lyell built upon the work of Hutton and greatly furthered the burgeoning science of geology. His key contributions include expanding on Hutton’s concept of uniformitarinism/geologic time as well as dabbling in volcanology, paleontology, and glaciology. He also traveled widely, even to North America where he made observations about geology in the colonies. He was also a friend and colleague of Charles Darwin and is believed to have contributed to the publication of On the Origin of the Species. I should add that many mountains have been named in his honour just in case that little tidbit sways your vote at all.

Charles Darwin

Darwin is without question the “Father of Evolution” but does this also qualify him to be the Father of Geology? Evolution is a central aspect of understanding deep time and how Earth’s biota has changed from the Hadean to now and why. Darwin also worked extensively on paleontology and in addition to On the Origin of the Species wrote several geology books about marine invertebrates, atoll formation by coral reefs and his observations during his travels on the Beagle.

Nicolas Steno

In addition to being the namesake of an entire profession, stenographer (kidding), the contributions Nicolas Steno made to the science of geology cannot be overstated. Especially by sedimentologists. His conception of the laws of superposition, original horizontality, cross relationships and lateral continuity are all central to the ideas of deep time, stratigraphy and how formations relate to one another in the field. Furthermore, his principles inspired the work of Hutton.

An illustration from Steno’s 1669 book Source

Pliny the Elder

Certainly the oldest member of this list, although this doesn’t necessarily mean he’s the most important. As one of the earliest recorded observers of the natural world a few notes about geology made it into his magnum opus, Naturalis Historia in which he discussed Roman mining techniques, prospecting for gold, mineralogy and crystallography, and how to detect a fake gemstone. He also covered geography, astronomy, agriculture, art and medicine. Not too shabby!

Worth an honourable mention is that he actually died in the eruption of Mt. Vesuvius. There is some controversy over how since none of his companions suffered the same fate but he either died trying to rescue some friends trapped near Herculaneum or because he wanted a closer look at Vesuvius and ordered a slave to kill him to avoid cooking to death.

Alfred Wegener

Mr. Jigsaw, Alfred Wegener, deserves to be on the list even though he was not technically a geologist. However, as the recognized originator of the idea of contintental drift he certainly deserves recognition especially now because he was ridiculed for his ideas at the time. It was not really until 1965 when J. Tuzo Wilson developed the supercontinent cycle and other evidence was incorporated that theory of plate tectonics became really proven and Wegener’s ideas fully accepted.

William Smith

In addition to having the most generic name on the list, William Smith is the originator of the geological map and known as the “Father of English Geology”. However, as geological maps are not the sole province of the UK maybe he gets your vote as the Father of all geology? A canal builder and coal miner, like James Hutton, smith noticed the strata he was digging through repeated predictably throughout England and was the first to map their outcrops. He also originated the idea of faunal succession in rock formations which today is still regularly applied in the concept of relative age dating.

Smith’s beautiful map delineating the strata of England and Wales (sorry Scotland) Source

Mary Horner Lyell

This poll is about the Father of Geology, but here is my vote for the Mother of Geology title: Mary Horner Lyell. Mary Horner Lyell, in addition to being the wife of nominee Charles Lyell was a very accomplished geoscience researcher in her own right and her contributions were critical to the writing and field work of Charles Lyell. They were quite a dynamic duo! She also contributed to Darwin’s work on barnacles and the study of glaciology with fellow female scientist Elizabeth Agassiz.

The assignment of the coveted title of Father of Geology is now in your hands. Choose wisely!

[polldaddy poll=”9276888″]

By the way, feel free to write another name and justification in the comments if you don’t like my options. This is by no means an exhaustive list. I strongly considered adding William Logan and J. Tuzo Wilson to get some Canadian content in there.

Ultimately, it doesn’t matter who the Father of Geology is (sorry voters). As Newton eloquently said, “if I have seen further it is by standing on the shoulders of giants.” This sentiment applies well here as it is irrelevant who really started it all. Rather, it is more important to realize that as the science of geology expands and grows in divergent and convergent directions we are all standing on one another’s shoulders through the sharing of ideas and knowledge. There is no single base to this pyramid just as there is no distinguishable pinnacle.

My DEFENCE! Follow live tweets with #129I @ 2:30pm ET

Matt Herod November 16, 2015

My PhD defence is this week (Wednesday) at 2:30pm ET. I am feeling pretty good about the whole thing but at the same time nervous. I just don’t know exactly what to expect. I have a sort of idea of what the questions might cover and where my assumptions or conclusions might be challenged. However, the uncertainty of all this is what is making me nervous.

Credit: XKCD

I have gotten lots of good advice from people such as “you are the real expert on the material” and “be confident and prepare a great talk”. All of this is great advice, however it doesn’t really help assuage the feeling that this is the most important talk I have ever given and the nerves that accompany that. Furthermore, despite the fact that I am now an expert on 129I I still have to convince four very smart people that I what I did was worthwhile and good science.

As far as my preparations go I have read lots of articles from fellow bloggers about how to prepare and what to think about and talked to postdocs in the lab. These have all been very helpful things to do, but at the end of the day I know that I will be the one standing at the front of the room and facing the steely gaze of the examiners (not really, they are all nice people). I have read over my thesis several times, prepared a list of possible questions, re-read key articles and reviewed the basic principles of the models I used and the statistical tests. I still feel unprepared and I doubt that feeling will go away until I start my talk. Plus, thesis committees are still scary!

Credit: PhD Comics

Anyway, in the interest of distracting myself yet also being sort of productive I am preparing to live-tweet my defence. I am pre-scheduling about 20-30 tweets for the time during my talk so you can view these key points of my thesis as I talk about them at uOttawa. Follow the feed with #129I. Interact with the tweets, ask questions, etc. I won’t get to them until later in the day…or maybe the next day, but I will eventually.

Wish me luck and remember, follow #129I!!!! Tweets start at 2:30pm ET.

Also, I’m using a new presentation program called SlideDog. I mean why not try something new for the most important talk of my life. Stay tuned for this:

Credit: PhD Comics